(1) Field of the Invention
The present invention relates to damper assemblies and more particularly relates to a damper assembly for use in gas-conducting conduits in gas treating installations.
(2) Description of the Prior Art
In large gas-conducting conduit systems such as those used in the cleaning of waste gases evolving from metallurgical and chemical operations, it is necessary, generally, to provide damper assemblies for controlling the flow rate of gases through the system. In many installations it is extremely important that reliable tight or nearly tight shut-off dampers be used. In flue gas cleaning systems for utility boilers, for example, dampers must be opened to permit the passage of flue gas through the ducts and must be closed to isolate flue gas cleaning equipment, such as, gas scrubbers, and by-pass the flue gas around the equipment to avoid shutdown of the utility boiler or other device. The damper must effectively isolate the equipment being by-passed so that the equipment can be safely inspected, and so that internal maintenance may be performed. Furthermore, in many applications, hot corrosive gases are present in the gas stream and upon cooling of the gas stream, particularly during shutdown, the corrosive gases condense thereby promoting corrosion of the damper assemblies.
In the prior art, complex and expensive sealing arrangements as well as expensive materials of construction for damper assemblies have been utilized.